THE 25-year-old woman who died after the Stereosonic music festival at Sydney Olympic Park is believed to have taken an ecstasy tablet and mixed it with MDMA while a 22-year-old woman has been discharged from hospital, after earlier being placed in an induced coma.

Paramedics rushed young pharmacist Sylvia Choi of Oyster Bay to Concord Hospital where she died last night.

She is believed to have taken an ecstasy tablet but also may have mixed MDMA in a bottle of water.

It may have taken up to 10 minutes to get Ms Choi off the dance floor and to a medical tent after she collpased, the Daily Telegraph reports.

“This madness has to end,” Premier Mike Baird said. “The idea of going out for a good night out is one thing, but when that night out ends with losing one of your friends you can’t put words on that stupidity.”

The commander of the police operation, Assistant Commissioner Frank Mennilli, said young people were playing Russian roulette with their lives.

“These drugs are made by criminals in back yards,” Assistant Commissioner Menilli said today.

“It’s like opening a bottle of bleach and swallowing it.

“People have to get out of the mentality that you have to take drugs to enjoy a concert.”

The two women were not at the concert together.

Ms Choi’s friends have told police they ingested a “tablet” but police have not said which drug they are suspected of taking.

More than 120 people were treated for the effects of drugs while nine were taken to hospital.

There were more than 200 police patrolling the event but only one quarter of those was paid for by the promoters with the rest of the cost, in the tens of thousands of dollars, being born by the taxpayer.

Even with a massive police presence there were still plenty of people who thought they could get past it. Picture: Jonathan NgSource:News Corp Australia

“The majority of the cost is born by me as the region commander. We have to provide a safe environment,” South West Region Commander Assistant Commissioner Frank Mennilli said.

“An extensive number of policing sources were there. If had more dogs and more police it would just result in more people being arrested.”

“A young woman has lost her life as we believe as a direct result of a drug overdose. We won’t know the full extent of the situation until an autopsy is conducted,” he said.

“I’d like to take this opportunity to pass on my condolences to the family and loved ones of the young person who passed away. It must be an extremely difficult time for them.

“It is extremely frustrating. We have been working hand-in-hand with the organisers, the venues, we put out numerous messages to try to warn people about the effects of drugs but unfortunately the messages sent do not get through to some people.”

Some 69 people were charged with drug supply and possession. Picture: Jonathan NgSource:News Corp Australia

During the 11-hour event which attracted 48,000 revellers and ran until midnight, 69 people were charged with drug supply and possession while another 23 were given cannabis cautions.

Assistant Commissioner Mennilli said he was unhappy with the results.

He said he had been asked why police sent out the same warnings about drugs and sniffer dogs before every big concert like this.

“We warn them about the risk but people don’t listen,” he said.

“People have to be protected from themselves.”

There were 200 police officers deployed to the site for the event. Picture: Jonathan NgSource:News Corp Australia

He said that anyone who criticised the use of sniffer dogs as a breach of civil liberties was ill-informed.

“I will continue to work extremely hard with the promoters and the venues to provide a safe environment but at the end of the day, it comes back to the individual making the right choices,” he said.

“The police operation is about minimising harm and providing a safe and secure environment for revellers to have a good time,” Inspector Mennilli said.

“We already have 69 people charged for drug possession and supply. This number is alarming and disappointing, especially after we warned revellers about the dangers of drug use.”

The death of the young woman comes just over a year after another death due to drugs at a festival when Georgina Bartter died after taking ecstasy at Harbourlife Festival.

Ms Bartter, 19, was found convulsing on the ground at the dance party at Mrs Macquarie’s Chair last November.

Her best friend Rebecca Hannibal was convicted of supplying the drug to Ms Bartter and given a 12-month good behaviour bond.

The concert’s promoters Totem Onelove group posted a brief statement on the Stereosonic Facebook page this morning about the death.

“Totem Onelove conveys our deepest condolences to the friends and family of the patron who tragically passed away on Saturday night at Sydney Stereosonic. As it is a matter with the NSW Police and Coroner we cannot make any further statements or comment. We appeal to our audience that they stay safe and look out for each other,” it read.

The Stereosonic tour headlined by Armin van Buuren, DJ Snake and Major Lazer will today go to Perth before moving onto Adelaide, Melbourne and Brisbane next weekend.

Galantis performs at Stereosonic.Source:Supplied

Over the past fortnight two men were caught trying to drill holes into walls at the festival site to allegedly stash drugs before it went into lockdown and special fencing was put up.

Security guards sprung Zane Raffie, 21, allegedly trying to drill a hole into a carpark wall and called police when he fled on November 20.

Police later went to his house and found 10 MDMA pills and charged him with malicious damage, trespass and a drug offence. He will appear in Burwood Local Court in February.

Officers were called back to Sydney Olympic Park on Tuesday night after security guards saw Ali Ghoneim, 22, acting suspiciously.

They allegedly found 95 ecstasy pills in his car and charged him with supplying a prohibited drug. He was granted conditional bail and will appear at Burwood Local Court on December 15.

The festival’s website states that ticket holders must leave Illicit or prescription drugs at home or ‘risk being ejected immediately without a refund, nor right to re-entry’.